HIRUNDINID.E — THE SWALLOWS. 355 



more independent of man than most of its family, owing liini no other favors 

 than those incident to excavations through sand-hanks, of which it avails 

 itself. The nests of these Swallows are placed in excavations made by 

 them in the banks of rivers, cliffs by the sea-shore, and similar favorable 

 situations. These are usually as near the surface of the ground as the 

 nature of the soil permits to be readily penetrated, though the bird has 

 been known to work its way even through hard gravel. Their depth varies 

 ironi fourteen inches to four feet, though two feet is the usual distance. 



Mr. Augustus Fowler mentions a remarkable instance of sagacity and 

 provident forethought in these birds, not easily separable from reason. In 

 the town of Beverly, in a stratum of sandy loam, he observed each season a 

 colony of some twenty or thirty pairs of these birds. In this place these 

 birds never burrowed more than two or three feet. Within a mile of this 

 place another colony excavated a bank in whicli the layer of loam was mixed 

 with small stones. In this bank they excavated to the depth of five, seven, 

 and even nine feet. Why was there this extraordinary difference in the 

 length of burrows made by the same species, in situations not more than a 

 mile apart ? The reason for this difference, upon examination, became very 

 obvious. We give the explanation in Mr. Fowler's own words : " In one 

 bank, where the earth was of a fine sandy loam, easily perforated, from the 

 entrance to the extremity the burrows did not exceed three feet in length ; 

 while in the other bank, with harder loam to work in, one burrow was found 

 nine feet in length. After examining six holes of nearly equal length, it 

 appeared that these little birds had sufficient reason for extending their labors 

 so far into the earth. In every instance, where they met with a spot free 

 from stones tliey finished their burrows ; thus showing great care lor the 

 welfare of their eggs or young by avoiding, in the stony soil, a catastrophe so 

 great as would befall their treasures if by accident one of these stones should 

 fall upon them." 



The work of perforation they perform with their closed bill, swaying the 

 body round on the feet, beginning at the centre and working outwards. This 

 long and often winding gallery gradually expands into a small spherical 

 apartment, on the floor of which they form a rude nest of straw and feath- 

 ers. The time occupied in making these excavations varies greatly with tlie 

 nature of the soil, from four or five days to twice that number. 



Their eggs are five in number, pure white, and wlien unblown have a fine 

 roseate hue. They are oval in shape, larger at one end, and pointed at 

 the smaller. Their average length is .72 of an inch, and their average 

 breadth .47. 



